A reaction product is provided, of reactants comprising: a) at least one copolymer comprising at least 30 mol % of residues having the following alternating structural units: -[DM-AM]-  wherein DM represents a residue from a donor monomer, AM represents a residue from an acceptor monomer, the copolymer containing pendant carbamate groups or groups that can be converted to carbamate groups; b) at least one aldehyde; and c) at least one monohydric alcohol; wherein when the copolymer (a) contains groups that can be converted to carbamate groups, the reactants further comprise: d) at least one material that will convert said groups into carbamate groups. The reaction product is suitable for use in a variety of curable compositions, which are also provided.